The class of polycarbonate polymers is broadly known in the art. An early review article by Schnell, Industrial and Engineering Chemistry, Vol. 51, No. 2, pp. 157-160 (1959) describes properties of the class of polycarbonates and methods known in the art at that time for the preparation of polycarbonate polymers including certain polycarbonate polymers which are now commercial. In general, the polycarbonate polymers are thermoplastics whose glass transition temperatures will depend upon the nature and symmetry of the groups incorporated into the polycarbonate chain other than the carbonyldioxy groups. Most polycarbonates are derived from a bisphenol and commercial polycarbonates are frequently derived from 2,2-di(4-hydroxyphenyl)propane, also known as bisphenol A or BPA. The polycarbonate polymers are conventionally produced by reaction of a bisphenol or an alkali metal salt thereof with phosgene or by ester exchange with a diaryl carbonate, particularly diphenyl carbonate.
These polymers ar processed by conventional methods employed for thermoplastics such as injection molding or extrusion into films, sheets, fibers, tubing and shaped articles. The articles produced from the polycarbonate polymers demonstrate good resistance to oxygen, heat and light as well as to common solvents. While some of the polycarbonate polymers have moderately high glass transition temperatures and thus could be marginally useful as engineering thermoplastics in applications where exposure to elevated temperatures is likely to be encountered, many of the polycarbonate polymers have sufficiently low glass transition temperatures so that the usefulness of such polymers is thereby limited. The commercial polycarbonate based on BPA has a glass transition temperature on the order of 150.degree. C., for example. It would be of advantage to provide a novel class of polycarbonate polymers of relatively high glass transition temperature and accordingly wider application.